Coating material spray device



Oct. 9- D. A. WALLACE COATING MATERIAL SPRAY DEVICE Filed July 12, 1937NAXM 1% WM, Aw m 0 m,

Patented Oct. 31, 1939 UNITED STATES PATENT OFFICE COATING MATERIALSPRAY DEVICE Application July 12, 1937, Serial No. 153,167

10 Claims.

This invention relates to improved coating material spray apparatus.

More particularly, the invention relates to coating material of spraydevices of the type from which atomized surface coating material isdischarged in a finely divided state.

One of the main objects of the invention is the provision of a rotatingnozzle in a spray device of this character, by which the spray dischargepattern may, in effect, be rotated.

Another object of the invention is the provision of a nozzle of thischaracter from which air may be discharged both for the purpose ofatomizing the surface coating material and bringing the discharge of thelatter to a predetermined pattern.

A further object of the invention is the provision of a spray device ofthis kind having a rotatable air nozzle provided with spaced outletsfrom which air currentsmay be so directed upon a discharged stream ofcoating material as to flatten the coating material dischargeprogressively in successively different directions in order to producethe effect of a. rotating flattened discharged pattern.

Other objects of the invention are the provision of improved means, in aspray device of this character, for rotating the nozzle thereof; toprovide fluid pressure operable means of this kind which may be suppliedwith fluid under pressure from the air passage of the normal spraydevice, or from an external independent course as desired; to provide ananti-friction rotative bearing structure for rotatably supporting thenozzle which is adapted to maintain the latter in concentricrelationship with respect to the surface coating material discharge tubethereof; and to provide valve mechanism for simultaneously controllingthe discharge of surface coating material and the supply of air to thenozzle and the supply of air to the mechanism by which the nozzle isdrivingly rotated.

Fig. 1 is a side elevational view, partly in sec-- tion, of a spray gunembodying the invention.

Fig. 2 is a transverse, vertical sectional view, taken on the line 2-2of Fig. 1.

Fig. 3 is a transverse, vertical sectional view, taken on the line 3-3of Fig. 1.

50 Fig. 4 is a side elevational view of part of the structure shown insection in Fig. 3.

Fig. 5 is a fragmentary, front end elevational view of the spray gun, asviewed from the plane designated by the line 5--5 in Fig. 1, anddiagrammatically illustrating the spray pattern and its rotative path ofmovement produced by the spray gun.

In the form of the invention illustrated in the drawing, the spraydevice comprises a main body portion, generally designated by thenumeral II], which conforms substantially to gun contour. The bodyportion I0 includes a handle part II and a discharge part I2, angularlydisposed with respect thereto. While the invention is disclosed inconnection with a manually manipulatable device, it should be understoodthat substantially all the advantages thereof, and in some instancesgreater advantages, are obtainable by employment thereof on an automaticor mechanically operated spraying device.

Extending continuously through the handle part I I and discharge part I2of the spray gun, is an air passage I3 to which compressed air may besupplied by a conduit, detachably connected to the lower end portion ofthe handle part II, as viewed in Fig. l. The outlet end I5 of the airpassage I3 communicates with an air chamber I6 located at the dischargeend portion of the device. The passage of air under pressure through thepassage I3 may be controlled by Valve mechanism, generally designated bythe numeral I! which is mounted on the upper end portion of the handlepart I I and which includes a cylindrical bore I8 in which a piston I9is slidably mounted. The piston I9 is secured to a stem 20 having anexternal end portion suitably attached to a trigger 2I which ispivotally mounted at 22 on the discharge part of the spray gun.

The valve bore I8 intersects the passage I3 and the piston I9 is adaptedto close the same to prevent the flow of air from the handle part II ofthe gun to the discharge part I2 thereof. The left end portion of thedischarge part I2 of the gun is provided with a coating material passage23 through which the valve stem 24 extends. The valve stem 24 isslidably mounted in a gland nut structure 25 andis operatively connectedwith the trigger 2I in order to facilitate simultaneous operation of thevalves ll and 24, respectively.

Provided on the right extremity of the discharge part I2 of the bodyportion of the gun is a coating material discharge tube 26 having afrusto-conical end portion 21 and an open extremity 28 which is adaptedto be closed by the tapered extremity 29 on the valve stem 24, when thevalve stem is in its rightward-most position. Suitable resilient means,not shown, may be employed for yieldably urging the valve stem 24 towardits closed position.

Threaded at 30 on the right extremity of the discharge part [2 of thebody portion of the gun, is a collar 3! having an end portion 32extending outwardly and serving as the peripheral wall of the compressedair chamber iii. A ring 33, provided with external threads 34, ismounted on the outer periphery of the collar 3| and located insubstantially radial alignment with the portion of the body portion partof the gun on which the collar 3i is threaded. A casing, generallydesignated by the numeral 35, is screw-threaded on the thread 3% of thering and provided with a cylindrical part 36 which substantiallysurrounds the discharge tube 26. The casing 35 has an inwardly extendinglip 3? on its right extremity, as viewed in Fig. 1, within which isconfined a race member 58 of a rolling contact element having a seriesof ball bearings 39 and an inner race member 40.

A hollow nozzle structure M is rotatably supported by the inner racemember Ml and held thereby, substantially in concentric relationshipwith respect to the coating discharge tube 26. The nozzle ii has acentral recess 42 on its inner end having an open extremity andsubstantially diametrically opposite lugs 33 on its outer end. Betweenthe recesses 42 and the inner end portions of the lugs 53 is provided arelatively thin wall structure M having a central opening 45 in which heouter reduced extremity of the coating material discharge tube as isreceived. The central opening 45 is slightly larger than the outerdiameter of the reduced end portion of the discharge tube 25 in order toprovide a substantially circular slot it around the outlet end portionof the discharge tube 2'5. Formed in the transverse wall structure M areinclined air passages 61 which converge rightwardly, as viewed in Fig.1, toward the course of the discharge from the tube 26. Formed in theannular Well portion 48 of the nozzle ll are a pair of diametricallyopposite air passages d9 which extend through the lugs 43 and which haveinwardly converging discharge end portions 58 so arranged as to directblasts of air from respectively opposite directions upon the coatingmaterial discharged from the tube 26. The slot 56, inclined air passages47, and outer air passages 45 all communicate with the air chamber itduring all positions of the nozzles relative to the body portion of thespray device during rotation of the nozzle.

A ring having an axially extending flange 5! is non-rotatably secured tothe left end portion of the nozzle 45 and disposed in a chamber 52located between the side planes of the race members 33 and l!) and theouter side face of the threaded ring 33. Provided on the left side faceof the flange 5! is a series of vane elements 53 by which the flange andnozzle ll attached thereto are adapted to be rotated. The ring 33 isprovided with a peripheral groove 5 2 from which extend air passages 55having outlet end portions communicating with the air chamber 52 andarranged so as to direct jets of air upon the vanes 53, the air beingexhausted to atmosphere through slots 33 in the casing 35. Theperipheral groove 54 is supplied with air, or other suitable fluid underpressure, through a fitting 56 mounted on the casing 35 and having apassage 51 leading to the peripheral groove 54. The outlet end portionsof the air passages 55 are so directed as to rotate the ring 59' andnozzle 4! fixed thereto in a predetermined direction.

In the form of the invention illustrated in the drawing, the fitting 56is connected by a flexible coupling 58 with an elbow-shaped fitting 59threaded in the main body portion of the spray device and having apassage therein which communicates with the air passage l3 of thelatter. In this form of the invention, the air current which is utilizedto rotate the spray nozzle 4! is derived from the same source as the airwhich is supplied to the nozzle of the spraying device. If it is desiredto supply air to the vanes 53 under a pressure or by a fluid mediumdifferent from that of the passage I3, the fitting 56 may be connectedwith any suitable source of fluid pressure (not shown).

The coating material is supplied to the interior of the passage 23 andto the discharge tube 26 by a conduit 66 which is connected with afitting 6! having a passage 62 therethrough leading to the passage 23.In the device shown in the drawing, the air supplied to the vanes, aswell as that supplied to the nozzle may be controlled by the trigger 2!simultaneously with control of the discharge of coating material fromthe tube 26.

In the operation of the foregoing paint spray device, when the trigger2i is moved in a clockwise direction from the position shown in Fig. 1,paint is discharged from the discharge tube 25 and a current of air isdischarged through the circular slot $8 to atomize the coating materialas it leaves the tube 26. Air supplied through the inner pair ofconverging and oppositely directed air passages 41 also aids to someextent in the atomizing of the discharge of the coating material. Thestreams of air discharged through the passages 41, however, togetherwith the air streams discharged from the passages 49, flatten the streamof coating material discharged so as to produce the elongated spraypattern illustrated at 63 in Fig. 5. Since these inclined and convergingair streams rotate in unison with the nozzle, they progressively flattenthe coating material discharge from successively angularly changedpositions so as to, in effect, cause the spray patterns 63 to rotateabout the axis of the nozzle 4| and about the axis of the discharge tube26 which is substantially concentric therewith. In this manner, theeffective spread of the spray discharge pattern is materially increasedand the distribution of the coating material upon the surface to whichit is applied is correspondingly improved. Less manual movement of thegun is required on the part of the workman and the hazard of building upexcessive thicknesses of coating material at isolated portions of thesurface being sprayed, by unintended hesitation of the workman duringmanipulation of the spray gun is greatly reduced.

Although but one specific embodiment of the invention is herein shownand described, it will be understood that various changes in the size,shape and arrangement of parts may be made without departing from thespirit of my invention.

What I claim is:

1. A coating material spraying device comprising a main body portionhaving passages therein for conveying coating material and air underpressure respectively, a nozzle rotatably mounted on said main bodyportion having a coating material outlet and having a pair of airpassages communicating with the air passage of said main body portionand provided with opposed air discharge orifices located in spacedrelation to and directed toward the axis of rotation of said nozzle inexternally converging relation with respect thereto and revolvable aboutsaid axis, and means for drivingly rotating said nozzle whereby saidorifices are revolved during operation of said spraying device. i I

2. A coating material spraying device comprising a main body portionhaving passages therein for conveying coating material and air underpressure respectively, a nozzle rotatably mounted on said main bodyportion having a coating material outlet adjacent its axis of rotationand having a pair of air passages communicating with the air passage ofsaid main body portion and provided with air discharge orifices locatedon opposite sides of said outlet and directed in converging relationtoward the path of discharge of and located outwardly from said coatingmaterial outlet and revolvable about the latter, means on said nozzleresponsive to a fluid pressure discharge for drivingly rotating saidnozzle, and a fluid pressure discharge member having an outlet adjacentsaid means.

3. A coating material spraying device comprising a main body portionhaving passages therein for conveying air under pressure and coatingmaterial respectively, a coating material discharge tube communicatingwith said coating material passage and having an outlet orifice fordischarging a stream of coating material from said device directly inadvance thereof, a nozzle rotatably mounted on said main body portionsubstantially in concentric relationship with respect to the outlet ofsaid discharge tube and provided with air passages having inlet endscommunicating with the air passage of said main body portion and outletends radially spaced from the rotative axis of said nozzle and soconstructed and arranged as to discharge air into said stream of coatingmaterial at a location externally of said nozzle, and means fordrivingly rotating said nozzle during operation of said spraying device.

4. A coating material spraying device comprising a main body portionhaving passages therein for conveying air under pressure and coatingmaterial respectively, a coating material discharge tube communicatingwith said coating material passage, a nozzle rotatably mounted on saidmain body portion substantially in concentric relationship with respectto the outlet of said discharge tube and provided with air passageshaving inlet ends communicating with the air passage of said main bodyportion and outlet ends radially spaced at diverse distances from therotative axis of said nozzle, the outlet end portions of said nozzle airpassages being inclined with respect to said rotative axis and to thecourse of coating material discharge from said tube for directing blastsof air in converging relationship upon said coating material discharge,and means for drivingly rotating said nozzle during operation of saidspray device.

5. A coating material spraying device comprising a main body portionhaving passages therein for conveying air under pressure and coatingmaterial respectively, a coating material discharge tube communicatingwith said coating material passage having an outlet for dischargingcoating material externally of said device, a nozzle rotatably mountedon said main body portion substantially in concentric relationship withrespect to the outlet of said discharge tube, said rotatable nozzlebeing provided with a plurality of air passages communicating with theair passage of said main body portion and having outlet end portions sodirected with respect to the discharge of coating material from saidtube as to converge with said coating material discharge at a locationexternally of said device and to maintain said discharge in apredetermined rotating non-circular pattern during rotation of saidnozzle, andmeans for drivingly rotating said nozzle.

6. A coating material spraying device comprising a main body portionhaving passages therein for conveying coating material and air underpressure respectively, a nozzle rotatably mounted on said main bodyportion having a coating material outlet for discharging a stream ofcoating material externally of said device and having a pair of airpassages rotatable in unison with said nozzle and communicating with theair passage of said main body portion and provided with opposed outletorifices for discharging streams of air from opposite directions uponsaid coating material discharge at a location externally of said device.air propellable vanes on said nozzle, means communicating with the airpassage of said main body portion and adapted to direct a discharge ofair on said vanes for drivingly rotating said nozzle during operation ofsaid spraying device, and valve mechanism in the air passage of saidmain body portion for simultaneously controlling the supply of air totheair passages of said nozzle and to the vanes thereof.

7. A coating material spraying device comprising a main body portionhaving passages therein for conveying air under pressure and coatingmaterial respectively, a coating material discharge tube communicatingwith said coating material passage, a nozzle rotatably mounted on saidmain body portion substantially in concentric relationship with respectto the outlet of said discharge tube and provided with air passageshaving inlet ends communicating with the air passage of said main bodyportion and opposed outlet ends radially spaced from and located onopposite sides of the outlet of said discharge tube for dischargingsubstantially oppositely directed air blasts upon the discharge fromsaid tube to bring the discharge pattern to a flattened contour, fluidoperable means on said nozzle for drivingly rotating the latter, andmeans for directing a blast of air upon said driving means.

8. A coating material spraying device including a main body portionhaving coating material and air passages therein, a coating materialdischarge tube communicating with said coating material passage andextending from one end of said spray device and having a dischargeorifice in its external end, an annular casing surrounding saiddischarge tube, a rotatable nozzle having air passages thereincommunicating with the air passage of said main body portion, and havingair outlets for directing streams of air against the coating materialdischarged from said orifice at a location externally of said device,means in said casing for rotatably supporting said nozzle, a propellingmember non-rotatably fixed to said nozzle and having vane elementsdisposed in said casing, and means for discharging fluid under pressureinto said casing and upon said vanes.

9. A coating material spraying device including a body portion, a fixedcoating material discharge tube, an air discharge nozzle rotatablymounted on said body portion and surrounding the outlet end portion ofsaid tube having air discharge outthe effect of rotating said dischargepattern is produced.

10. A coating material spraying device including a body portion, an airdischarge nozzle rotatably mounted on said body portion, a fixed coatingmaterial discharge tube on said body portion having a discharge passageextending axially of said nozzle for discharging a stream of coatingmaterial in a direction generally parallel to the axis of rotation ofsaid air nozzle, said air nozzle having a pair of opposed rotating airoutlets spaced from and directed toward said axis for dischargingstreams of air from opposite directions in courses converging externallyof said device with said stream of coating material, and means fordrivingly rotating said nozzle during spraying operations.

DAVID A. WALLACE.

